.d1 {
  width: 800px;
  height: 300px;
  background: #ccc;
  margin: 0 auto;
}
.d1 h1 {
  text-align: center;
  height: 80px;
  line-height: 80px;
}
.d1 p {
  font-size: 20px;
  font-weight: bold;
  text-align: center;
}
.d1 p a {
  text-decoration: none;
  color: white;
  margin-left: 20px;
}
.d1 p a:hover {
  text-decoration: underline;
  color: #ff7300;
}
/*
    继承，有两种写法
*/
.a,
.b {
  color: red;
  font-size: 20px;
}
.a span,
.b span {
  font-style: italic;
  font-family: 楷体;
}
.a h2,
.b h2 {
  background-repeat: no-repeat;
  background-position: center right;
}
.c,
.b {
  font-weight: bold;
  text-indent: 10px;
  overflow: hidden;
  background-size: cover;
}
.b {
  background: #ccc;
  text-decoration: underline;
}
